How do I evaluate and treat pica, including assessment and correction of iron‑deficiency anemia and zinc deficiency, behavioral management, and indications for psychiatric referral or SSRI therapy?

Evaluation and Treatment of Pica

Screen for and aggressively correct iron deficiency anemia and zinc deficiency in all patients with pica, as these micronutrient deficiencies are strongly associated with pica behavior and treatment typically resolves the condition within weeks.

Initial Assessment

Laboratory Evaluation

• Measure hemoglobin and complete iron studies including serum ferritin, transferrin saturation, and serum iron to identify iron deficiency anemia 1, 2
• Check plasma zinc levels as hypozincemia is present in approximately 45% lower concentrations in pica patients compared to controls 2
• Ferritin <45 ng/mL with hemoglobin <13 g/dL (men) or <12 g/dL (non-pregnant women) confirms iron deficiency anemia 3
• Mean serum ferritin in pica patients averages 7.17 ng/mL with mean hemoglobin of 8.7 g/dl 4

Identify Pica Substance and Pattern

• Document specific substances ingested: most commonly raw rice, ice cubes (pagophagy), clay/earth (geophagy), or raw starch (amylophagy) 4, 1
• Assess frequency, duration, and age of onset of pica behavior 2
• Evaluate for gastrointestinal blood loss through stool testing, as this may contribute to iron deficiency 4
• In menstruating females, assess for excessive menstrual bleeding as a contributing factor 4

Treatment Approach

Iron Replacement Therapy

• Initiate oral iron supplementation immediately in patients with confirmed iron deficiency 3, 4
• Ferrous iron salts (ferrous sulfate, ferrous fumarate, ferrous gluconate) are reasonable first-line choices 3
• Iron is absorbed better on an empty stomach; if not tolerated, take with meals or with 500 mg vitamin C to enhance absorption 3
• Consider intravenous iron for patients with active inflammation, previous oral iron intolerance, hemoglobin <100 g/L, or malabsorption conditions 3

Zinc Supplementation

• Supplement zinc in patients with documented deficiency or clinical signs including growth retardation, increased infections, delayed sexual maturation, or anorexia 3
• Zinc is best tolerated in divided doses throughout the day 3

Expected Response

• Pica typically disappears within a few weeks of adequate iron supplementation, even before complete biochemical correction of iron deficiency 4
• Pica is associated with 2.35 times greater odds of anemia (95% CI: 1.94-2.85) and significantly lower hemoglobin (-0.65 g/dl), hematocrit (-1.15%), and zinc concentrations (-34.3 μg/dl) 1

Monitoring and Follow-Up

Short-Term Monitoring

• Recheck hemoglobin and ferritin within 1-3 months to verify improvement 3
• Continue monitoring pica behavior resolution as iron stores are repleted 4

Long-Term Monitoring

• Monitor for recurrent iron deficiency every 3 months for at least one year after correction, then every 6-12 months thereafter 3
• Goal is to maintain hemoglobin and serum ferritin within normal range 3
• Re-initiate treatment when ferritin drops below 100 μg/L or hemoglobin falls below gender-specific thresholds 3

Psychiatric Considerations

When to Consider Psychiatric Referral

• Pica persisting despite correction of iron and zinc deficiencies warrants psychiatric evaluation 4
• Underlying mental disorders, psychiatric conflict, or severe behavioral components may require specialized management 5
• DSM-IV excludes mild pica tendency associated with mental disorders from the formal diagnosis of pica 5

SSRI Therapy

• No evidence supports routine SSRI use for pica in the provided guidelines
• Reserve psychiatric medications for cases with documented underlying psychiatric disorders requiring treatment 5

Important Caveats

• The causal relationship between pica and micronutrient deficiency remains bidirectional: pica may cause deficiency through impaired absorption, or deficiency may trigger pica behavior 1, 6
• Pica is more prevalent in lower socio-economic classes and may be masked, requiring direct questioning in at-risk populations 4
• One study found pica did not affect gastrointestinal iron absorption, suggesting iron deficiency causes pica rather than vice versa 6
• In rare cases (approximately 1 in 17 patients), pica may persist despite adequate iron replacement, necessitating behavioral or psychiatric intervention 4